Interaction between cyclosporine and grapefruit juice requires long-term ingestion in stable renal transplant recipients.
OBJECTIVE
To examine the effect of the concurrent administration of increasing amounts of grapefruit juice, an inhibitor of drug metabolism, on the steady-state pharmacokinetics of cyclosporine.


METHODS
Open-label, three-period crossover, food-drug interaction study in stable renal transplant patients.


METHODS
A university-affiliated clinical research center.


METHODS
Sixteen stable renal transplant recipients.


METHODS
Cyclosporine was administered with 240 ml of water, 240 ml of grapefruit juice, or several 240-ml glasses of grapefruit juice, and serial blood samples were taken to estimate the effect of grapefruit juice on cyclosporine pharmacokinetics.


RESULTS
Grapefruit juice caused a significant increase in cyclosporine area under the curve, however, no significant effect was seen in other pharmacokinetic parameters. Grapefruit juice caused an increase in the 24-hour trough cyclosporine concentration, which may be of clinical significance if long-term ingestion of grapefruit juice is recommended.


CONCLUSIONS
A drug interaction exists between cyclosporine and grapefruit juice, and it is likely at the level of intestinal drug absorption.
Brunner
L J
LJ
Pharmaceutics Division, College of Pharmacy, University of Texas at Austin, 78712-1074, USA.
Munar
M Y
MY
Vallian
J
J
Wolfson
M
M
Stennett
D J
DJ
Meyer
M M
MM
Bennett
W M
WM
D000328:Adult; D019540:Area Under Curve; D001628:Beverages; D002957:Citrus; D016572:Cyclosporine / Q000493:pharmacokinetics* / Q000627:therapeutic use; D005260:Female; D018565:Food-Drug Interactions; D006801:Humans; D007166:Immunosuppressive Agents / Q000493:pharmacokinetics* / Q000627:therapeutic use; D007676:Kidney Failure, Chronic / Q000378:metabolism / Q000628:therapy; D016030:Kidney Transplantation / Q000502:physiology*; D008297:Male; D008875:Middle Aged
D007166:Immunosuppressive Agents; D016572:Cyclosporine